This invention relates to disposable food contact compatible microwaveable containers having at least one micronodular surface including cups, trays, souffle dishes, lids, plates, bowls, and related articles of manufacture useful for preparation, storage, delivery, and serving of food, wherein convenience and low cost are of paramount importance. Nevertheless, appearance and tactile characteristics of the plate, container, etc., are important for consumer preference. The suitability of these disposable articles of manufacture for microwave cooking, or heating of food, has an important place in today's marketplace. Both the commercial and retail market components need an aesthetically pleasing microwaveable, disposable, rigid and strong container, plate, or cup, and related article of manufacture. This invention is directed to economically meeting that need and provides a container or plate comprising an extruded sheet of a polyolefin selected from the group consisting of polypropylene, polypropylene polyethylene copolymer or blend, or a mixture of these coupled with mica or a similar platy inorganic mineral.
These disposable microwaveable containers and plates exhibit (a) a micronodular surface on the food contact side of the plate or container, and (b) a melting point of no less than about 250.degree. F., said container or plate being dimensionally stable and resistant to grease, sugar, and water at temperatures up to at least 220.degree. F. and exhibiting sufficient toughness to be resistant to cutting by serrated polystyrene flatware. Microwaveable and disposable containers and plates having all the aforementioned properties are not known in the prior art. In U.S. Pat. No. 5,377,860, assigned to assignee of the present patent application, a double shell food container is disclosed. The composition and properties of the container differ from the present invention since a polyolefin/mica composition is not suggested or disclosed and the container does not have the thermal properties or the micronodular surface of the containers disclosed herein. The containers disclosed in European Patent Application D544,429A1 do not suggest or disclose a container which can meet the thermal properties and have the desirable micronodular surface of the container of the present invention.